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What are the mysterious light sources on light pollution maps?
- robbrown451 7y agoYou'd think they'd do better at containing the light from the grow houses, so more ends up on the plants and less making it to space. Like, foil or something?
- teilo 7y agoI mean, people who grow pot figure out how to hid the light, so yeah.
- ct520 7y agoor do they.. Did you see all the light up in northern cali? LOL
- deleted 7y ago[deleted]
- crazygringo 7y agoSince these are greenhouses they have to be clear to let the light in during the day, I assume. Anything that's going to reflect light to prevent it from leaving at night will also block the sun from hitting the leaves during the day, unless it's a complicated mechanical system that can be folded up during the daytime. I'm guessing such a reliable mechnical system together with maintenance is much more expensive than the light leakage.
- coderintherye 7y agoThere are systems on the market that are not too complicated. We have an iGrow system for instance for our greenhouse. But yes, the covers do tend to snag and such when rolling up and that can be problematic and require maintenance. Definitely though the industry does not seem to have yet embraced automation much.
- Moru 7y agoGreenhouses are early adopters of automation. But they only automate the stuff that actually works reliably. This means watering schedule, fertilizer and light. There are few things mechanical that can go wrong with them, especially the light part. They don't have a hord of maintenance people that have time to fix everything that goes wrong. They might have one person that is doing that beside other things. I live close to one of the bigger ones in north Sweden. They run some accelerated daytime schedule in the darkess of the polar winter so at least part of the nights has a yellow sky in the whole area. You see it for 10 km on the way to the village nighttime. Could almost believe it's a 100 k town but no :-)
- coderintherye 7y agoYes, good to note my perspective is on greenhouses in the US, I think greenhouses in Europe are definitely more automated, especially in Amsterdam!
- throwaway9d0291 7y agoWhat about that electrically controlled darkening glass like they use for windows on some of the newer planes?
- zdragnar 7y agoThat is insanely expensive compared to the more standard poly that gets used, and something as simple as a hail storm night shatter the glass and ruin an entire crop. I imagine some cheap opaque sheet metal, solar panels and 24/7 artificial lighting would be cheaper than mega-greenhouse amounts of specialty glass.
- ficklepickle 7y agoFoil isn't as reflective as one would guess. Mylar or even matte white painted surface are better. It really surprises me, too. I guess the sheer size of these operations make it difficult or impractical. The cost must be greater than that of the wasted light. Too bad, because that is a lot of wasted light.
- derefr 7y agoOne thing I'd like to see is a light-pollution map of the US overlaid with a map of all US federal land. To answer the question: what's the brightest thing the federal government is doing?
- TeMPOraL 7y agoSubcontracting. I mean, I half-expect all the interesting projects to be contracted out.
- reaperducer 7y agoI'm not sure that's a way to find the answer you're looking for. I expect that a lot of the brightest spots on federal land will be mining operations conducted by private companies.
- c3534l 7y ago> what's the brightest thing the federal government is doing? There's a cynical joke in there somewhere.
- AnimalMuppet 7y agoSome of it is burning off natural gas in oil-producing regions.
- rabuse 7y agoI was looking at light pollution maps just the other day, trying to find places to do astro-photography, and was blown away by how much light pollution there is. Really sucks, because I'd have to drive about 90 minutes out to get into a dark zone.
- donkeyd 7y agoOnly 90 minutes? For me it's at least 3 hours to get to Class 4 on the Bortle scale. Class 2 is probably more than 5 hours. Only alternative is the sea. I'm planning to take a trip to a Class 1 this summer, it'll be hard to find a place that dark that is reasonably reachable though.
- AdamJacobMuller 7y agoNYC? About the same for me.
- krick 7y agoExactly, this almost sounds like humblebragging (I know it's not, but still...) I mean, in the whole EU you literally couldn't find a place with Class 1 at all, unless going far-far North into Finland national parks or Norwegian mountains. Makes you hate civilization.
- bjelkeman-again 7y agoAccording to Darksitefinder northern Sweden seems better. There are som great places to go up there in the winter that is well worth trying.
- Moru 7y agoYes, every time we go visit my mother we stop on the road and look up, it's beautiful. No villages for 15 km and only darkness around. And a car passing by with ten headlights blinding you every now and then...
- ourlordcaffeine 7y ago
- twic 7y agoI flew through the night to Singapore once. I remember two very striking light sources. Firstly, oil well flares in the Middle East. The oil fields are in the middle of nowhere, so they're these huge orange-red blooms set in utter darkness. Secondly, Delhi. The city is brightly lit with streetlights. But there's a suburb (?) to the south, Faridabad, that's as brightly lit, but with a different, whiter, kind of lights. So you had these two huge blotches of yellow and blue light projecting into each other. There are also some extremely bright areas to the south of the city - after some investigation, I decided they were probably rock-crushing plants.
- 3JPLW 7y agoChicago has been slowly replacing its yellow sodium streetlamps with efficient LEDs that project down instead of up. They've been working block-by-block in a systematic way that you can see when you fly into the city at night. It's quite dramatic.
- paulie_a 7y agoDid Chicago figure out the issue with LEDs and snow. The old lights melted snow, the LED lights did not
- jschwartzi 7y agoChicago plows.
- ceejayoz 7y agoSnow on the lights, not the roads. I discovered LED headlights on cars don’t melt off the ice like incandescent do the last time I drove in an ice storm.
- reaperducer 7y agoThe LED and snow issue is about traffic lights, which are horizontal and therefore subject to getting filled with blowing snow. Streetlights face down and don't have a cavity to fill with snow.
- Raphmedia 7y agoHere in Canada, many tomato greenhouses have been converted to cannabis greenhouses. Some areas have lost their night sky because of this, as they have all grown quickly and use the same kinds of light arrays discussed in this article.
- amatecha 7y agoAh yeah, in the post's first "unknown light pollution" example, I figured it must be a greenhouse. I was driving through a relatively small town one time and was a bit freaked out by this ominous yellow glow off in the distance. Like, the whole sky was glowing [0]. I ended up driving out to try to find the source, and discovered it was a huge greenhouse/farm. Luckily not an extraterrestrial landing zone or so on ;) [0] looked like this https://i.cbc.ca/1.4925044.1543460834!/fileImage/httpImage/image.JPG_gen/derivatives/original_1180/night-sky.JPG https://i.cbc.ca/1.4925044.1543460834!/fileImage/httpImage/i...
- jaclaz 7y agoIconic scene in "Saving Grace": https://www.youtube.com/watch?v=3eMYxkEtxlM https://www.youtube.com/watch?v=3eMYxkEtxlM
- yread 7y agoYellow glow is understandable, but check out this purple one https://www.cbc.ca/news/canada/windsor/not-northern-lights-greenhouse-glows-1.4924468 https://www.cbc.ca/news/canada/windsor/not-northern-lights-g...
- amatecha 7y agoAh yeah, that's exactly where I got the above photo from. The purple glow is ridiculous! At least the yellow is a little less "abrasive" and more natural-looking.
- snazz 7y agoPurple makes sense. Blue and red are the colors of light that are most effectively absorbed by chlorophyll-pigmented plant leaves. Yellow would be a lot less efficient because more would reflect off the green leaves.
- robocat 7y agoMagenta is the complementary (opposite) color of green.
- hermitcrab 7y agoOn https://www.lightpollutionmap.info/ https://www.lightpollutionmap.info/ there is a big pollution area in Russia, North of Khazakstan. There doesn't seem to be a city. Is this an oil field? One of the patches is at 67 degrees 42' N, 83 degree 47' E.
- uhnuhnuhn 7y agohttps://en.wikipedia.org/wiki/Vankor_Field https://en.wikipedia.org/wiki/Vankor_Field
- hermitcrab 7y agoMystery solved. Thanks!
- deathanatos 7y ago> Kiluaea (sic?), as an active volcano, regularly has literal glowing lava occupying the caldera. Not anymore, sadly: https://www.nps.gov/havo/planyourvisit/lava2.htm https://www.nps.gov/havo/planyourvisit/lava2.htm > Beginning in May, 2018, the lava lake that existed inside Halema‘uma‘u crater disappeared and lava flows from Puʻu ʻŌʻō crater have ceased. There is no molten lava or lava glow to see anywhere in or out of the park. (I would still recommend visiting: the road that encircles the volcano is destroyed, and parts of it are hike-able, and the destruction is fun. And the caldera is even bigger now, and the sulfur vents are interesting, and the landscape is beautiful. And Hawaiʻi is just breathtaking.)
- krick 7y agoI wonder if there are some other places in the world I could visit reasonably expecting to see molten lava and all that dramatic looking stuff.
- jamiek88 7y agoIceland is your best bet.
- ComputerGuru 7y agoThe list of permanent lava lakes posted by and onychomys includes none in Iceland. https://en.m.wikipedia.org/wiki/Lava_lake https://en.m.wikipedia.org/wiki/Lava_lake
- onychomys 7y agoThere are currently seven permanent lava lakes: https://en.wikipedia.org/wiki/Lava_lake https://en.wikipedia.org/wiki/Lava_lake
- donatj 7y agoSeveral years ago I noticed that the northern edge of Alaska was lit up like Vegas on one of these light pollution maps. I was very curious what the heck this was and took to Google Maps. Found that it was oil fields as well. I'd personally assumed lighting for workers however and not gas flares. - https://www.lightpollutionmap.info/#zoom=5&lat=10294175&lon=-16288830&layers=B0FFFFFTFFFFFFFF https://www.lightpollutionmap.info/#zoom=5&lat=10294175&lon=...
- deepsun 7y ago> with an enormous array of yellow lamps Do they really need yellow? Plants do not really need green light (that's why leaves usually reflect green they don't need), so they'd probably be ok with red/blue lamps only. So why yellow? https://en.wikipedia.org/wiki/Grow_light https://en.wikipedia.org/wiki/Grow_light
- detaro 7y agoI guess they use sodium-vapor lamps because they're common and quite efficient, which happen to be yellow?
- Igelau 7y agoYou'd probably be right if they were only concerned with the growth of greenery. It's possible that the light needs of a flowering/fruiting tomato plant are different. It's also likely that the work of the humans and the bees is easier in something closer to daylight.
- TallGuyShort 7y agoA lot of fracking sites near me have exceptionally bright lights at night when they're being actively worked on. I suspect the brightness shown might be regular old electric lights, not just gas flares.
- dylan604 7y agoCar parks are notorious light polluters as well. These are large parking lots where car manufacturers off load cars by rail for their "last mile" delivery to the area dealerships. The lights are meant to keep the thief away. On top of the horrendous light pollution, they also cause massive* traffic headaches where the trains can come to a complete park for 20-30 minutes while the train cars with autos are connected/disconnected. *The one I lived near was in a pretty small town, so the traffic might have been only 10-15 cars on either side of the tracks. Massive is directly proportional to your direct involvement of being stuck.
- pbhjpbhj 7y agoYou mean loading cars on to trains? Surely they have sidings?
- dylan604 7y agoI don't know how they remove the automobiles from the train cars. This isn't what makes the train stop. It is the disconnect of the train cars with automobiles from the train so they can be moved to another set of rails that lead into the car park.
- flashman 7y agoYou absolutely can (or could) see the Kīlauea's glow from Mauna Kea, especially if there were clouds for it to refract through, as you can see from the first photo in this article: https://www.nytimes.com/2016/10/04/science/hawaii-thirty-meter-telescope-mauna-kea.html https://www.nytimes.com/2016/10/04/science/hawaii-thirty-met...
- aasasd 7y ago> At the time it wasn’t labeled on google maps That's exactly what OpenStreetMap is good for, at least where I am.
- divbzero 7y agoFascinating article! Constellations of fishing boats can also be a significant source of light when viewed from space. Here are examples from NASA of fishing boats off the coasts of Argentina [1] and Thailand [2]. [1]: https://earthobservatory.nasa.gov/features/Malvinas https://earthobservatory.nasa.gov/features/Malvinas [2]: https://earthobservatory.nasa.gov/images/92152/fishing-in-green-living-in-yellow https://earthobservatory.nasa.gov/images/92152/fishing-in-gr...
- tzs 7y agoThe map of the United States raises an interesting question. There is a pretty distinct line down the middle, with nearly opposite light/dark patterns on different sides of the line. To the east, it is mostly bright areas with islands of dark. To the west, it is mostly dark areas with islands of bright. If you look at a regular map, nothing really stands out to explain the difference. It is not like there is, say, a mountain range or difficult to cross river or something running down the boundary that made travel or settlement westward much more difficult at that point. So why did patterns change there? I asked about this once before, and received a few answers. I'm not sure if any of them are the actual explanation or not, though [1]. [1] https://news.ycombinator.com/item?id=12345439 https://news.ycombinator.com/item?id=12345439
- BurningFrog 7y agoYeah, there is a pretty distinct line from Winnipeg to San Antonio, separating light from dark. If you look at a population density map, it looks quite similar: http://dafi1637.blogspot.com/2017/10/united-states-population-heat-map.html http://dafi1637.blogspot.com/2017/10/united-states-populatio... I think that explains the immediate effect. You can of course then wonder why the population is distributed that way, but I feel I've done enough here :)
- dylan604 7y ago>Yeah, there is a pretty distinct line from Winnipeg to San Antonio, separating light from dark. That's the I-35 corridor. An interstate highway running north/south all the way from Mexico to Canada. It was probably the most hyped/utilized part of NAFTA. I live in Dallas where I-35 runs through (actually splits in Waco to cover both Dallas and Ft. Worth, reconnecting north around Denton). I grew up in a small city south of Dallas, and remember all of the highway construction that got spurred by NAFTA. That area (Ellis county) also had a construction boon due to the Super Conduction Super Collider.
- duderific 7y agoMy guess would be that the land is not as conducive to farming west of that line, both in terms of soil and weather. So early settlements didn't occur there, and thus cities did not emerge from those areas. The cities that did evolve in the West were based on different resources: ports around the ocean, mining, oil, railroad stops etc.
- ipqk 7y agoDarvaza Gas Crater: https://www.lightpollutionmap.info/#zoom=8.363333333333332&lat=4902271&lon=6483116&layers=B0FFFFFTFFFFFFFF https://www.lightpollutionmap.info/#zoom=8.363333333333332&l...
- eternalny1 7y agoI've been dealing with heatmaps on a personal pet project of mine: https://www.wingswatch.net/heat-map/2019 https://www.wingswatch.net/heat-map/2019 We are swimming in data these days, articles like this are fascinating.
- gitgudnubs 7y agoCool, it seems that US tomato farms produce as much light as North Korea.
- transect 7y agoMy favorite mysterious light sources is a triplet off the coast of Newfoundland: https://www.lightpollutionmap.info/#zoom=6&lat=5798060&lon=-5275970&layers=B0FFFFFTFFFFFFFF https://www.lightpollutionmap.info/#zoom=6&lat=5798060&lon=-... I assume it's some sort of offshore rig.
- zhdc1 7y agoLight analysis is surprisingly noisy.If you want to do it right, you have to screen out or control for cloud cover, reflections, moon light, oil well fires, and also account for satellite position and the local time at night the image was originally taken. The first four, particularly the first, are easier said than done (e.g., still waiting for NASA to publicly release VNP46A2).
- zsellera 7y agoAs someone working in the greenhouse lighting industry, I might have some insight on this: 1. there is an existing technology called energy screen/curtain, with the primary function of retaining heat, but can also reduce light pollution by an order of magnitude. 2. light that escapes is essentially money lost, however it alone does not justify the use of energy screens. 3. as long as farmers have access to (relatively) cheap heat and electricity, they won't invest into this technology. 4. for the time being, it's a regulatory issue, just like water use (a single plant use 2-2.5 l/day), supplemental co2 use and nitrate recirculation from runoff water.
- bjelkeman-again 7y agoWater use and nutrient recirculating can be lowered dramatically with aquaponics, even CO2 use can be lowered in some configurations. It comes with added complexity and capex, but should be financially sustainable.
- hedora 7y agoIn addition to wasting energy, light pollution at night is killing off insects, which (along with other factors, like neonicotinoids and habitat loss) is leading to ecosystem collapse. For instance, North America’s bird population has dropped by 25% since 1970. Insects fared significantly worse over that period, but exact numbers are harder to come by.
- mrmuagi 7y ago> 4. for the time being, it's a regulatory issue, just like water use (a single plant use 2-2.5 l/day) Is the 'plant' there a, say, tree or is it referring to the whole building?
- zsellera 7y agothat's per a single tomato plant, summer time. I guess it's the same for any greenhouse crop, see the reasoning here: water use is necessary to manage internal climate. the greenhouse was designed to keep heat inside. the plants have to cool themselves (hence the environment) by evaporation. the farmer manages evaporation rate by watering, temperature and humidity. there are many feedback loops, both negative and positive, balancing it is a non-trivial task. btw. there's an average of 1.2-1.3 plant/m2 in most tomato greenhouses I've seen.
- mango7283 7y agoWhat are all the light sources in the ocean between Taiwan and South Korea? I'd assume shipping, but what about the other shipping lanes, those don't look so obvious compared to that piece of ocean
- sandos 7y agoSquid fishing maybe? "Fishing trials using LEDs (9 kW) and different numbers of MHs were carried out in August and September 2009" from https://www.researchgate.net/publication/256998066_Catch_performance_of_coastal_squid_jigging_boats_using_LED_panels_in_combination_with_metal_halide_lamps https://www.researchgate.net/publication/256998066_Catch_per...
- mango7283 7y agoPerhaps, that's a vast area for that though.. interesting. ( It's most obvious using the viirs 2019 overlay on lightpollutionmap.info )
- macqm 7y agoI can't figure out one light pollution source in Poland in Sluchowo (54.77550N, 17.94972E). The map from 2015 shows some factory of sorts, but it disappears on the map from 2020, all you can see is an outline what it was. I really wonder what kind of place this was and why it emitted relatively a lot of light.
- aasasd 7y agoOpenStreetMap doesn't have anything there, but Wikimapia has a ‘Shale Gas Drilling Rig’ nearby (‘Wiertnia Gazu Łupkowego’).
- macqm 7y agoBingo you got it. https://infolupki.pgi.gov.pl/en/whats-drilled/news/3legs-resources-published-results-production-tests-made-lublewo-lep-1sth https://infolupki.pgi.gov.pl/en/whats-drilled/news/3legs-res...
- f1refly 7y agoMost likely some kind of military operation. It could be a storage site, guarded 24/7 where light is important so the guards can see everything clearly.
- pbhjpbhj 7y agoIs this just tradition? Surely a computer system can see/hear, maybe using night-vision (lidar? radar?), way better than guards can. Then lights can activate and guards can shoot at anyone unwanted who crossed the perimeter .. surely enough incentive?
- ncmncm 7y agoUsed to be a huge bright spot way the hell north in Canada, on one of the islands. I finally IDed it as an enormous open-pit lead mine. The site was finally mined out after producing millions of tons of lead.
- perilunar 7y agoSince no one has mentioned them yet: a shout out to The International Dark-Sky Association: https://www.darksky.org https://www.darksky.org
- batirch 7y agoWe drive 2.5 - 3 hours to Abu Dhabi deserts to watch milky way. It is nearly impossible to enjoy dark sky in Dubai.
- divbzero 7y agoI live on the other side of Earth but can fully sympathize with your long drive. It’s a shame that the Milky Way is so difficult to see in most cities around the world. It is truly majestic: not only visually stunning but also awe-inspiring when you realize you’re gazing across the void at the next arm of our galaxy.
- Moru 7y agoAnd I complain about having to drive 20-30 minutes to get real darkness, puts some perspective in there.
- deleted 7y ago[deleted]
- dwd 7y agoIt's a bit like this satellite image of Australia: https://eoimages.gsfc.nasa.gov/images/imagerecords/80000/80030/australia_night_201204-10.jpg https://eoimages.gsfc.nasa.gov/images/imagerecords/80000/800... Some of what they have labelled as fires could be from mining but there is literally nothing out there as far as human population.